An evaluation of soil properties which enable aggregates to resist breakdown from impacting water-drops is useful in modelling soil erosion process and in evaluating the suitability of tillage implements for different soils. The objectives of this study were (i) to identify the main soil properties which confer stability on aggregates of typical mediterranean soils from central Italy and (ii) to develop and validate empirical models for predicting the resistance of aggregates of these soils to water-drop impacts (D) from such soil properties. Air-dry aggregates (2–4 mm in diameter), collected from 15 surface (0–20 cm) soils in north central Italy were used for this study. The actual and natural log-transformed D values were regressed on the soil properties. Clay content, wilting point moisture content (WP) and percent water-stable aggregates (WSA)>2.0 mm were good predictors of D. Empirical models developed from either clay content or WP predicted D in 70% of the test soils whereas the model developed from WSA>2.0 mm predicted D in 90% of the test soils. The correlation coefficients (r) between measured and predicted D were 0.961, 0.963 and 0.997 respectively, for models developed from clay, WP and WSA>2.0 mm. Hence a quick inference on the resistance of these and similar soils to water-drop impacts can be made from information on these easily-determined properties.
Soil and Tillage Research 05/1998; 45(1-2-45):133-145. DOI:10.1016/S0933-3630(96)00133-X